C— GEOLOGY 69 



individual is to all intents and purposes the evolution of its species seen 

 through the wrong end of the telescope ; or conversely that the evolution 

 of a species (or any larger group) is but the life of one of its members 

 extended into geological perspective. 



This generalisation may appear to some to suffer from over-attractive- 

 ness ; it seems too simple to be true. Such an attitude would imply that 

 individual life is simple — an absurd travesty of the truth. But even if it 

 were, the history of all scientific research teaches that simplicity is a 

 characteristic of Nature, and complexity a reflex of human ignorance. In 

 the physical world a few simple principles work uniformly on galaxies and 

 atoms ; it is only to be expected that in the organic world there should be 

 a common control of the lives of phyla and cells. The same law of 

 dynamics controls a see-saw or the Tower Bridge ; why should not one 

 law of evolution apply equally to individuals and to the races to which 

 they belong ? These arguments seem reasonable, but they would be 

 mere sophistry were not the facts of Palaeontology explicable on no other 

 assumption. In the light of our knowledge, we are justified in declaring 

 that the way ' life ' is lived is the way of evolution, whether it be from 

 the Cambrian to the Holocene or from the cradle to the grave. 



It is unnecessary to enlarge upon the corollary to this conception. If 

 all living things are in continuous contact with varying conditions, those 

 that are adaptable will enjoy greater prospects of success than those that 

 are stereotyped. Youth implies plasticity, and old age is synonymous 

 with stiffness. Whether physically or mentally, the young are flexible, 

 the old more rigid ; changes of circumstance that stimulate a youth will 

 kill his grandfather. In evolution this means that a group will, in its 

 early stages, be able to keep pace with, and be moulded by, its changing 

 environment, while when it has passed its prime it will be in deadly 

 danger from similar changes. Although we are far from an understanding 

 of the mechanism by which this result is attained, the result itself, and its 

 causes, are repeated a myriad times in the palaeontological record. 



In view of the fragmentary evidence afforded by Palaeontology, any 

 attempt to produce a ' genealogical tree ' for an individual or group must 

 be largely speculative, and of doubtful value. It is hard enough to trace 

 the descent of human beings whose ancestors were born in recorded 

 wedlock ; but the mating of most creatures, particularly of marine in- 

 vertebrates, achieves a degree of promiscuity unattained even in Hollyr 

 wood. Nature is no stud-farm ; and, although there are stern laws to 

 limit hybridisation, cross-breeding is infinitely complex. Those who 

 seek to detect lineages among fossils are seeking the non-existent. 



In his address to this Section in 1920, my late friend and mentor 

 Dr. F. A. Bather laid stress on the distinction between succession and 

 descent. He illustrated the danger of confusing the two concepts by 

 reference to the succession of English sovereigns, where logical adherence 

 to a well-founded theory of descent would ' make James I the son of 

 Elizabeth.' This mistake would be disreputable in the light of known 

 facts ; but, with all deference to the memory of the Virgin Queen, it would 



